In November 2011, Benchmark's chief engineer, John Siau, had lunch at an audio engineering conference with two friends from THX, and by the end of it they had written the specifications for a new power amplifier on a napkin. That amplifier became the AHB2. Siau points out that ordinary feedback fixes an error only after it happens. The AHB2 pairs a big amplifier that supplies the power with a small one that compares the output with the input and cancels the difference as it happens. That matters most at the fraction of a watt that carries most music, and Siau's double-blind tests found that small errors at those levels were clearly audible to most listeners. Audio Science Review's founder ranked the AHB2 the best amplifier he had measured. Benchmark tells buyers who want "a warm veil of even-harmonic distortion" that they have come to the wrong place. Its gear suits listeners who want the recording unchanged, and Erich Wetzel of SoundStage! Hi-Fi heard "nothing more, nothing less" than the recording through the LA4 preamp.

Most Benchmark systems are built around a DAC3 converter. The B is the plain version, the L adds analog inputs and a volume control, and the HGC adds a headphone amplifier. What Hi-Fi? called the HGC "the one to go for" for anyone who needs analog inputs. Pair it with the AHB2. It takes balanced XLR inputs only, but on its high gain setting a simple RCA-to-XLR adapter works. It makes 100 watts into 8 ohms, and bridged as a mono amp it makes far more, for speakers of 6 ohms or more. Check the DAC3's output level, which is set with internal jumpers. Carlo Lo Raso of Secrets used the full studio level into an all-Benchmark stack, and ConvinceMeAudio advises turning it down for other amplifiers. If you listen quietly, add the LA4 preamp. HiFi Turtle found its advantage over the DAC's own volume control at low listening levels, and his wife noticed the change without being told.

Benchmark began in 1983 as the Benchmark Sound Company, in a garage in Garland, Texas, where Allen H. Burdick built audio equipment for television broadcast facilities. It moved to Burdick's hometown of Syracuse, New York, where its products are still designed, assembled and tested. Its DA101 was a distribution amplifier built to feed 10 balanced lines at once, and the company used DA101s to drive its listening-room speakers for years because it couldn't buy a better amplifier. Siau joined in 1997 after 15 years designing video systems for CBS. Home listeners found Benchmark through the DAC1, which Alan Sircom of Hi-Fi+ calls one of the first products that took USB audio seriously. Stereophile's John Marks introduced it in 2003, and it stayed in the magazine's Class A recommendations for well over a decade. The THX amplifier still had no name in September 2013, when its faceplates were ready to print. Siau noticed that its class A performance, class H rails and class AB output stage spelled out A, H and B, Burdick's initials, and the project called PA2 became the AHB2.